<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Essai</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<script type="text/javascript" language="javascript">

function remove_col2() {

var colp = document.getElementById("colp");

var c4= document.getElementById("c4");



colp.colSpan=0;

colp.style.display="none";

c4.style.display="none";







}

function remove_col() {
var tr1 = document.getElementById("tr1");

var tr2 = document.getElementById("tr2");

var tr3 = document.getElementById("tr3");

var colp = document.getElementById("colp");

var c1 = document.getElementById("c1");

var c2 = document.getElementById("c2");

var c3 = document.getElementById("c3");

var c4= document.getElementById("c4");



c1.style.display="none";

colp.colSpan=1;

c3.style.display="none";

c2.style.display="none";

document.documentElement.offsetHeight;

remove_col2();

}



</script>
</head>
<body onload="remove_col()">
<table border="1" id="t_0">
  <thead>
    <tr id="tr1">
      <th rowspan="2">aaaa</th>
      <th rowspan="2">bbbb</th>
      <th colspan="2" id ="colp">cccc</th>
      <th rowspan="2">dddd</th>
    </tr>
    <tr id="tr2">
      <th id="c1">eeee</th>
      <th id="c2">ffff</th>
    </tr>
  </thead>
  <tbody>
    <tr  id="tr3">
      <td>1111</td>
      <td>2222</td>
      <td id="c3">3333</td>
      <td id="c4">4444</td>
      <td>5555</td>
    </tr>
  </tbody>
</table>

</body>
</html>
